With the huge expansion in biotechnology, gel electrophoresis has become an indispensable tool. The ability to separate nucleic acid fragments and proteins by means of size, shape and charge has added numerous opportunities to identify specific compounds, indicate purity, and allow for isolation of a compound in relatively pure form. By being able to change the conditions under which one carries out the electrophoresis, one can determine many characteristics of the compounds in the sample.
A variety of new techniques are predicated on the use of gel electrophoresis in an efficient and convenient way. Restriction fragment length polymorphisms is one application where one can perform genetic diagnosis by means of a genomic DNA sample. This technique may also be used in forensic medicine to identify the source of nucleic acids. gel electrophoresis may also be used to identify a compound, by separation of a complex mixture and then by using markers, such as antibodies, or the like. Electrophoresis is used in conjunction with transfer to a membrane such as Southern, Northern, and Western blotting, or other techniques involving transfer of the separated sample to a different substrate.
While much of the power of gel electrophoresis as a tool in identification and separation is realized, there are still many shortcomings. Apparatuses tend to be relatively large and cumbersome. Comparisons from samples or runs and particularly from different laboratories are very difficult since conditions of the electrophoresis vary and regulation and monitoring of the conditions is not available or unreliable. Thus, one frequently gets wide variations in determinations of molecular weight, as well as the properties of the sample components. Therefore, it has been very difficult to make comparisons from one run to another, no less from one laboratory to another. Also, the gel electrophoretic apparatus usually does not prevent the sample from running off the gel, nor does it provide assurance that the sample has had sufficient time for a reasonable separation. Thus, substantial improvements in presently available equipment is desirable in order to obtain a satisfactory electrophoretic separation.
There is substantial interest in being able to provide electrophoretic systems which can be substantially automated, assure directly comparative results, and provide economies in the use of electrophoresis.